I want to to put a K&N intake 57 series in my durango part number 57-1538. I heard it may not do anything and was just wondering what anyones thoughts might be?

 

It will make the air flow better into the engine for combustion. It is noticeable as your engine may idle a little lower than with the stock intake,
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It will give a bit more horsepower, but you would need to more modifications such as exhaust headers to let the waste gas escape easier as well as a cat-back exhaust. 16HP seems high, but I would say atleast 5-8 HP. You are allowing more air to enter the combustion chamber, but it is being restricted in the stock manifold and exhaust system. This is back pressure and it makes the engine work harder to expel the waste gasses,
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